1. Field of the Invention
The invention relates to ice for use in beverages, and related methods for making and using such ice. More specifically, the invention relates to ice for use in cooling beverages wherein one wishes to include caffeine, and related methods for making and using such ice.
2. Description of the Related Art
The use of ice, i.e., water in its frozen or solid state, for cooling beverages of course is extremely well known. Commercially-available beverage ice is usually manufactured, typically in ice making machines, and thus controls can be exercised regarding purity, geometry or shape, texture and the like. Beverage ice comes in a variety of geometric shapes or forms. Some of the more popular varieties include square-faced or cubic, rectangular-faced or cuboid, spherical, hemispherical, crescent-shaped, tubular, flaked or crushed ice, and others.
It is common in public beverage serving establishments to fill a beverage glass with ice, and then to pour the beverage components (a soft drink, liquor components, mixers, etc.) into it on top of the ice. Typically, the ice is added up to the top rim of the glass, and the beverage component or components are added, either in specific, measured amounts or in approximate amounts by visual inspection. In some instances, a remaining volume of the glass is filled with a mixer, such as water, soda, juice, etc. There are also instances where a lesser amount of ice is used, such as an amount that would be sufficient to fill only about a third or half of the beverage glass, and instances where a beverage is first poured into a glass and ice is then added. The liquid beverage components, which may be referred to simply as “beverage,” often are at ambient temperature when dispensed into the glass. Thus, some melting of the ice occurs promptly, and the process of heat transfer and melting then occurs. Stirring or agitation may be used to modify and enhance the process.
The usual function of beverage ice of course is to cool the beverage. The ice is colder than the beverage, and when the beverage and ice are combined, heat from the beverage is absorbed by the ice, thus reducing the temperature of the beverage. It should be noted that the ice initially may be at a temperature below its melting or fusion temperature. For pure water at atmospheric pressure, the melting point or fusion temperature is 0° centigrade (“C”) or 32° Fahrenheit (“F”). The ice may, however, be cooled below this point. As is well known in such fields as physical chemistry and thermodynamics, for ice below its fusion temperature, as heat is added, the temperature of the ice will increase in inverse proportion to its heat capacity or specific heat. For pure water at standard temperature and pressure, the specific heat capacity is 1.00 calories per gram-degree centigrade (cal/g/° C.). For ice consisting of pure water at atmospheric pressure, the specific heat is 0.50 cal/g/° C. That is, if one calorie of thermal energy is inputted into one gram of ice, this input will cause the temperature of the ice to rise by 0.50° C. As additional heat is slowly added, the temperature of the ice will rise until it reaches the melting point or fusion temperature of 0° C. (32° F.). At this fusion temperature, the addition of further thermal energy will not cause the temperature of the ice to rise, but instead will cause it to transition from solid state to liquid state, i.e., to change its phase from solid to liquid, or melt.
In the context of ice in a beverage, upon mixing, the beverage is usually at a temperature that is higher than that of the ice. Thus, given that heat is transferred from higher temperature regions to lower temperature regions, heat in the beverage is transferred across the solid-liquid boundary at the surface of the ice and into the body of the ice, i.e., the bulk ice. This heat transfer process causes the temperature of the beverage to decrease and the temperature of the ice to increase substantially without melting until the fusion temperature of the ice is reached at its surface. At that temperature, the additional heat transferred from the beverage to the ice causes the surface of the ice to melt. Because the associated heat of fusion is 80 cal/g/° C., the melting of ice absorbs 80 calories (“cal”) of heat energy from the surrounding beverage for each gram (“g”) of ice melted. As a result, the principal part of the cooling effect of beverage ice derives from melting. This melted ice, or liquid water, is then physically diffused or convected away from the ice surface and into the bulk liquid of the beverage.
When a room temperature beverage and ice are mixed, the amount of ice melted during the “initial cooling phase,” defined herein as the cooling of the beverage from its initial temperature to about 40° F. (4.4° C.), will vary somewhat according to several factors. These factors include the temperature of the beverage when poured and the starting temperature of the ice. Another cause for variation is that cooling of an alcoholic beverage can require the melting of up to about 13% less ice than would be required with a non-alcoholic beverage due to reduced specific heat capacity resulting from the alcohol content. As a general approximation, however, for each gram of beverage that is cooled in the initial cooling phase, about 0.20 to 0.26 grams of ice melt. These amounts result from the above-described thermodynamic phenomena.
A beverage might be cooled with the exact amount of ice that, on complete melting, would cool the beverage to the desired drinking temperature. In most instances that amount would be similar per gram of beverage to the values given above. Ordinarily, however, a greater amount of ice than this is used, e.g., about 0.5 to about 1.5 grams of ice per gram of beverage. Amounts of ice such as these can provide faster cooling, a reserve cooling capacity to keep the beverage cool during the period of drinking even as some heat is absorbed from the environment, and there is typically economic advantage to a proprietor compared to minimal use of ice, since for a given beverage container size less beverage needs to be dispensed to fill the container. Personal preference could be another reason for such use.
Caffeine is a well-known and widely-used chemical, often used or consumed in beverages. It functions as a stimulant to the central nervous system. Short term effects include increased energy and alertness, which many find to be desirable or advantageous.
In caffeine-containing beverages caffeine concentrations are ordinarily in the range of about 2.8 to 5.9 milligrams (“mg”) per fluid ounce (“oz”) (mg/oz) of beverage for carbonated soft drinks, about 10 to 17 mg/oz for non-espresso coffee, about 3.8 to 7.5 mg/oz for teas, and about 9.4 to 16 mg/oz for typical eight-ounce energy drinks. A minimal advantageous dose that may be consumed at one occasion can be considered to be about 23 mg, corresponding to 8 ounces of a caffeinated soft drink such as Coca-Cola®. More commonly, however, those wishing to enjoy the advantages of caffeine typically consume about 50 to 100 mg of caffeine per serving, and when consuming more than one serving, from about 50 to about 250 mg of caffeine at an occasion. The maximum safe amount of caffeine consumed at one occasion is widely considered to be about 300 mg. In terms of concentration of caffeine in a beverage, the Food and Drug Administration has determined that caffeine may be used safely in beverages at concentrations of up to 0.02%.
Typically, for those who wish to consume a caffeine-containing beverage, they select a beverage that has the caffeine already included or incorporated into the beverage. A coffee drink would be an example. The caffeine is a component of the coffee bean from which the coffee beverage is made, and caffeine therefore is inherently incorporated into the beverage from the outset. Energy drinks provide additional examples, wherein caffeine is inherently included in the beverage, or is added during the beverage manufacturing process.
Alternatively, a non-caffeine-containing beverage may be converted to a caffeine-containing beverage, or the amount of caffeine already present in a beverage may be increased, simply by adding caffeine. The caffeine may be in solid form, e.g., such as a powder, a tablet, a capsule, etc. Chocolate, for example, usually contains caffeine, and could be dissolved into a beverage as a caffeine-providing component. The caffeine also may be in liquid form, typically contained in a solution. Adding a caffeine-containing energy drink to a non-caffeine-containing beverage would be an example. To illustrate, one may wish to add a small amount of energy drink to an alcoholic beverage to enjoy the benefits of the caffeine while enjoying the beverage.
This general approach of adding caffeine to a preexisting beverage at or near the point of consumption, however, can be disadvantageous in a number of respects. It is necessary, for example, for the caffeine component to be made physically present and available at the point of addition. If the addition is to occur in a restaurant, bar, lounge or other public establishment where drinks are served, for example, the caffeine component must be procured and maintained as a separate item of inventory. Caffeine is not generally available on a small scale for use as a beverage additive in a non-industrial setting. Further, addition of caffeine in the most commonly-produced pure form, which is powdered or crystalline, generally requires stirring for full dissolution to occur, and even then dissolution may be slow. In the context of professional establishments serving beverages, it is generally impractical for servers to spend more than a threshold minimum amount of time to prepare a beverage. For example, even 30 seconds of added preparation time in many cases is commercially unacceptable, and in nearly all cases disadvantageous.
Another disadvantage of adding caffeine powder to a beverage is that in many instances, beverages are carbonated or include a carbonated component such as a cola soda or tonic water. Carbon dioxide gas is dissolved in the liquid. The addition of caffeine powder to such a beverage provides seed or nucleation particles, which cause the dissolved gas to become less soluble and be released from the liquid phase. This results in sudden fizzing and significant loss of carbonation.
Yet another disadvantage of direct addition of caffeine involves safety and health. Concerns have been raised recently about excessive doses of caffeine in beverages. Indeed, deaths are presently being attributed by some to energy drinks containing large amounts of caffeine. A common guideline is that nutritional supplements, inclusive of energy drinks, should not contain more than 300 mg of caffeine per serving. Another guideline is that, in beverages, the caffeine concentration should be no greater than 0.02%.
Where caffeine itself can be added to a beverage, it is possible, whether by error or intention, for larger amounts of caffeine to be added than would be healthy or safe.
In some instances, caffeine-containing beverages have been frozen. Caffeine-containing colas, for example, have been frozen to yield a frozen slush or solid ice that contains the caffeine from the cola. In such instances, however, the caffeine is dispersed homogeneously within the ice cubes or particles. Some caffeine is delivered, but much of it remains in the unmelted ice left in the container after the beverage has been consumed. In the example described herein above, that could include about 50% or more of the caffeine initially in the cola. Generally, such ice essentially acts as a frozen beverage source which, on melting, provides the same beverage in liquid form. In some instances, ice used to cool a beverage has comprised a frozen caffeine beverage or aqueous caffeine solution and has provided caffeine to beverages in the melting process. For example, a caffeine-containing soft drink such as Coca-Cola® or a relatively more concentrated aqueous caffeine solution could be frozen into ice cubes without employing features of the invention. If such ice cubes are mixed with a beverage and the beverage cooled by them, some caffeine is released into the beverage according to the proportion of such ice that melts. Such ice, if used to cool a beverage, would in most cases release into the beverage within the first few minutes of drinking only from about 15%-50% of the contained caffeine. If the caffeine amount released by such ice in the first few minutes of drinking were a desired amount, then with further melting while drinking the beverage, the amount of caffeine consumed could exceed the desired amount by a large factor, even by five times. Such a wide potential variation in caffeine delivery could present a health risk in some cases, and is disadvantageous in nearly all cases. Accordingly, there is a need for means to provide a controlled, desired amount of caffeine for a broad range of instances of drinking a beverage where it is desired to add caffeine to the beverage.